To react to increased workloads and increase streaming units, consider setting an alert of 80% on the SU Utilization metric. Also, you can use watermark delay and backlogged events metrics to see if there is an impact.
Note: Backlogged Input Events: Number of input events that are backlogged. A non-zero value for this metric implies that your job isn't able to keep up with the number of incoming events. If this value is slowly increasing or consistently non-zero, you should scale out your job, by increasing the SUs.
Reference:
https://docs.microsoft.com/en-us/azure/stream-analytics/stream-analytics-monitoring

https://learn.microsoft.com/en-us/azure/azure-sql/database/sql-insights-enable?view=azuresql

Extended Events is a lightweight performance monitoring system aimed at collecting data for monitoring and troubleshooting SQL Server problems.
To capture SQL Server queries and the users who executed them using Extended Events, you can configure an event session with the sql_statement_completed event and the sql_server_login event, as well as add actions to collect relevant information.
Step 1: Open SQL Server Management Studio (SSMS)
Step 2: .In Object Explorer locate the SQL Server named sq12345678.
Step 3: Create a New Event Session:
In SQL Server Management Studio, navigate to Management > Extended Events > Sessions, right-click, and select "New Session".

Step 4: Define Events:
sql_statement_completed: This event captures information about completed SQL statements. It will provide the SQL query text and other details.
sql_server_login: This event captures login information, including the username and IP address.
Step 5: Add Actions:
* sql_statement_completed:
Add actions like collect_system_time, collect_statement_text, collect_database_id, collect_principal_name, and collect_login_name to gather specific data.
Add an action to capture the client application name (e.g., collect_application_name).
* sql_server_login:
Add actions like collect_principal_name, collect_login_name, collect_session_id, and collect_client_hostname to capture login details.
Step 6: Select the Data Storage page, Choose Targets:
event_file: Store captured events in a file (blob) in Azure Storage for persistent storage and analysis using SSMS XEvent Profiler. [Select sa12345678 by using the browse button]

Step 7: Configure and Start:
Set the desired filter conditions (e.g., duration of queries) [skip] and start the event session.
Reference:
https://learn.microsoft.com/en-us/sql/relational-databases/extended-events/quick-start-extended-events-in-sql-server
https://www.mssqltips.com/sqlservertip/6550/capture-executions-of-stored-procedures-in-sql-server/
https://www.sqlshack.com/using-sql-server-extended-events-to-monitor-query-performance/

Automatic tuning SQL Server identifies and fixes performance issues caused by query execution plan choice regressions. Automatic tuning in Azure SQL Database and SQL database in Microsoft Fabric also creates necessary indexes and drops unused indexes.
Step 1: To enable automatic tuning on a server in Azure SQL Database, navigate to the server in the Azure portal [Select sql12345678] and then select Automatic tuning in the menu.

Step 2: Select CREATE_INDEX, and change it to enabled.
Enable automatic tuning on server
On the server level, you can choose to inherit automatic tuning configuration from "Azure Defaults" or not to inherit the configuration. Azure defaults are FORCE_LAST_GOOD_PLAN enabled, CREATE_INDEX disabled, and DROP_INDEX disabled.
Step 3: Click the Apply button.
Automatic tuning options on a server are applied to all databases on this server. By default, all databases inherit configuration from their parent server, but this can be overridden and specified for each database individually.
Reference:
https://learn.microsoft.com/en-us/azure/azure-sql/database/automatic-tuning-enable